阿尔茨海默病正电子显像剂^(11)C-6-OH-BTA-1的制备

preparation of amyloid-beta imaging agent ^(11)C-6-OH-BTA-1

目的研究脑内β-淀粉样蛋白的 PET 显像剂[N-甲基-^(11)C]2-[4′-(甲氨基)苯基]-6-羟基苯并噻唑(^(11)C-6-OH-BTA-1)的制备路线。方法使用^(11)C-三氟甲基磺酰甲烷(Triflate-CH_3)进行^(11)C 标记,分别采用"反应瓶"法和"loop 环"法制备^(11)C-6-OH-BTA-1,应用 C18 cartridge 柱提纯产品。结果 2种方法从加速器开始生产^(11)CO_x 到生成 ^(11)C-6-OH-BTA-1的时间相近,分别为33和32min,按照加速器生产925 MBq^(11)C-Triflate-CH_3计算,未校正^(11)C 衰变的情况下,无色澄清^(11)C-6-OH-BTA-1注射液的产率为16%～44%,放化纯为92%～93%。结论使用"loop 环"法制备^(11)C-6-OH-BTA-1,方法简单易操作。

Objective It is hypothesized that the surplus of amyloid-beta （Aβ） in the brain leads to neuronal degeneration and dementia. A novel PET tracer N-methyl-11^C-2-（ 4＇-methylaminophenyl ） -6- hydroxybenzothiazole （11^C-6-OH-BTA-1 ） has been reported useful in the evaluation of these Aβ plaques. This study aimed at designing a better preparation method for this PET tracer. Methods 11^C-Triflate-CH3 was bubbled into the reactor of an automated remotely controlled radiosyntbesizer module, which contained reaction materials either in a V-tube or in a loop. The reaction was completed under different conditions. The radiolabelled products were purified by a small solid-phase cartridge. Results The whole preparation process took about 33 min from 11^COx to 11^C-6-OH-BTA-1 by using either method. The radiochemical purity was Between 92% - 93% and radioactivity concentration was over 185 MBq/ml. The loop method achieved a higher productivity than the other method. Conclusion The preparation and purification procedures of 11^C-6-OH-BTA-1 can be more effectively carried out by the captive loop method.